High loft, low center-of-gravity golf club heads

Abstract

A golf club and golf club head having a high static loft angle, low forward center of gravity, and enhanced z-axis gear effect via a large roll radius and/or tightly controlled moment of inertia about the CG x-axis, Ixx, associated with upward and downward twisting of the club head.

We claim: 
     
       1. A golf club head, comprising:
 a body defining an interior cavity, a sole portion positioned at a bottom portion of the golf club head, a crown portion positioned at a top portion, a forward portion and a rearward portion, and a face positioned at the forward portion of the body, the face having a varying thickness of no greater than 5 mm; 
 wherein the body has a volume greater than 250 cm 3 ; 
 wherein the face has a static loft angle; 
 wherein the golf club head has a center of gravity that is 5-20 mm below the geometric center of the face of the golf club head as measured along a z-axis of the golf club head having an origin at the geometric center; 
 wherein a projection of the center of gravity is located on the face and at an elevation below the geometric center of the face; 
 wherein the golf club head has a Delta 1 value of less than or equal to 25 mm; 
 wherein the golf club head has a moment of inertia about a golf club head center-of-gravity x-axis, I xx , of 150-500 kg-mm 2 ; and 
 wherein, at a normal address position, the sole portion is inclined at a sole angle of 5-40 degrees relative to a ground plane, such that a lowest point on the sole portion is at or near a rearmost point on the sole portion, and the sole portion slopes upward from the lowest point to a frontmost point on the sole portion. 
 
     
     
       2. The golf club head of  claim 1 , wherein the Delta 1 value is at least 10 mm and the moment of inertia about the golf club head center-of-gravity x-axis, Ixx, is at least 200 kg-mm 2 . 
     
     
       3. The golf club head of  claim 2 , wherein the moment of inertia about the golf club head center-of-gravity x-axis, I xx , is no more than 250 kg-mm 2 . 
     
     
       4. The golf club head of  claim 1 , wherein the volume is less than 460 cm 3  and a head weight is less than 210 grams. 
     
     
       5. The golf club head of  claim 1 , wherein a first portion of the body located at least partially above the geometric center of the face is formed of a non-metallic material having a non-metallic material density and a first portion thickness, and a second portion of the body located at least partially below the geometric center of the face is formed of a metallic material having a metallic material density that is at least twice the non-metallic material density. 
     
     
       6. The golf club head of  claim 5 , wherein at least a portion of the sole portion is formed of the metallic material having a sole thickness, and at least a portion of the sole thickness is at least twice the first portion thickness. 
     
     
       7. The golf club head of  claim 1 , wherein the sole portion is inclined at a sole angle of about 7 degrees to about 30 degrees relative to a ground plane. 
     
     
       8. The golf club head of  claim 1 , wherein the sole portion is inclined at a sole angle of about 10 degrees to about 25 degrees relative to a ground plane. 
     
     
       9. The golf club head of  claim 1 , wherein the sole portion is inclined at a sole angle of about 15 degrees to about 22 degrees relative to a ground plane. 
     
     
       10. The golf club head of  claim 1 , wherein the center of gravity is at least 7 mm below the geometric center of the face of the golf club head as measured along a z-axis of the golf club head having an origin at the geometric center. 
     
     
       11. A golf club head, comprising:
 a club head body having an external surface with a heel portion, a toe portion, a crown, a sole, and a ball striking face having a thickness no greater than 5.0 mm; 
 wherein the wherein the body has a volume greater than 250 cm 3  and the ball striking face has a static loft angle; 
 wherein the ball striking face of the club head body has a geometric center; 
 wherein the golf club head has a center of gravity that is 5-20 mm below the geometric center of the face of the golf club head as measured along a z-axis of the golf club head having an origin at the geometric center; 
 wherein the golf club head has a Delta 1 value of 10-25 mm; 
 wherein the golf club head has a moment of inertia about a golf club head center-of-gravity x-axis, I xx , of 150-500 kg-mm 2 ; 
 wherein a first portion of the body located at least partially above the geometric center of the face is formed of a non-metallic material having a non-metallic material density and a first portion thickness; 
 wherein a second portion of the body located at least partially below the geometric center of the face is formed of a metallic material having a metallic material density that is at least twice the non-metallic material density; and 
 wherein, at a normal address position, the sole portion is inclined at a sole angle of 5-40 degrees relative to a ground plane, such that a lowest point on the sole portion is at or near a rearmost point on the sole portion, and the sole portion slopes upward from the lowest point to a frontmost point on the sole portion. 
 
     
     
       12. The golf club head of  claim 11 , wherein the moment of inertia about the golf club head center-of-gravity x-axis, I xx , is no more than 250 kg-mm 2 . 
     
     
       13. The golf club head of  claim 11 , wherein at least a portion of the sole portion is formed of the metallic material and has a sole thickness, and at least a portion of the sole thickness is at least twice the first portion thickness. 
     
     
       14. The golf club head of  claim 11 , wherein at least a portion of the face is formed of non-metallic composite material. 
     
     
       15. The golf club head of  claim 11 , wherein the volume is less than 460 cm 3  and a head weight is less than 210 grams. 
     
     
       16. A golf club, comprising:
 a shaft having a grip at one end and a golf club head at the other end; 
 the golf club head having a body defining an interior cavity, a sole portion positioned at a bottom portion of the golf club head, a crown portion positioned at a top portion, a forward portion and a rearward portion, and a face positioned at the forward portion of the body, the face having a thickness of no greater than 5 mm; 
 wherein the body has a volume greater than 250 cm 3 ; 
 wherein the face has a static loft angle; 
 wherein the golf club head has a center of gravity that is 5-20 mm below the geometric center of the face of the golf club head as measured along a z-axis of the golf club head having an origin at the geometric center; 
 wherein the golf club head has a Delta 1 value of less than or equal to 25 mm; and 
 wherein the golf club head has a moment of inertia about a golf club head center-of-gravity x-axis, I xx , of 150-250 kg-mm 2 ; 
 wherein the golf club head has a roll radius; and 
 wherein, at a normal address position, the sole portion is inclined at a sole angle of 5-40 degrees relative to a ground plane, such that a lowest point on the sole portion is at or near a rearmost point on the sole portion, and the sole portion slopes upward from the lowest point to a frontmost point on the sole portion. 
 
     
     
       17. The golf club of  claim 16 , wherein a first portion of the body located at least partially above the geometric center of the face is formed of a non-metallic material having a non-metallic material density and a first portion thickness, and a second portion of the body located at least partially below the geometric center of the face is formed of a metallic material having a metallic material density that is at least twice the non-metallic material density. 
     
     
       18. The golf club of  claim 17 , wherein at least a portion of the sole portion is formed of the metallic material having a sole thickness, and at least a portion of the sole thickness is at least twice the first portion thickness. 
     
     
       19. The golf club of  claim 17 , wherein the Delta 1 value is at least 10 mm and the moment of inertia about the golf club head center-of-gravity x-axis, Ixx, is at least 200 kg-mm 2 . 
     
     
       20. The golf club of  claim 19 , wherein the volume is less than 460 cm 3 , the face thickness varies, and a head weight is less than 210 grams.